1. Field of the Invention
The present invention relates to a dart board assembly, and more particularly, to a dart board assembly which makes a front dart board positioned on a rear board rotate smoothly while making them not separate due to the vibration occurring at the rotation of the front dart board.
2. Description of the Related Art
Generally, as illustrated in FIG. 1, a rotary dart board includes a rear board 1, and a front dart board 2 having a longitudinal shaft 3 extending rearward from the back of the front board 2. The longitudinal shaft 3 is inserted within the central opening of a ball bearing 10 which is securely contained in a circumferential recess 4 extending forward from the rear board 1. The longitudinal shaft 3 of the front dart board 2 is directly connected to the ball bearing 10 via a washer 7 and a screw spike 6 inserted into an engaging recess 9 formed at the back of the central axis of the shaft 3. This structure is problematic in that the screw spike 6 engaged to the engaging recess 9 is easily loosened by the vibration occurring at the rotation of the front dart board 2, and thus the front dart board 2 is separated from the rear dart board 1, or the vibration phenomenon becomes more critical.
In addition, as illustrated in the drawing figure, since the height of the central shaft 3 is larger than that of the circumferential projection of the front dart board 2, it is not easy to load and store the front dart board 2 in a disassembled state prior to assembly and production.
It is, therefore, one object of the present invention to provide a dart board assembly which can restrict separation of a front dart board from a rear board and the occurrence of vibration during the rotation of the front dart board. The front dart board may rotate smoothly and can be easily loaded and stored in a disassembled state.
To achieve the above and other objectives, there is provided a dart board assembly, comprising: a rear board including a first panel, said panel defining an opening at an intermediate location of the first panel, the rear board further including a cylindrical projection extending rearward from a rear surface of the first panel, the cylindrical projection formed coaxially with the intermediate opening and defining an inner opening; a bearing positioned within the inner opening of the cylindrical projection of the rear board; a front board including a second panel, the front board further including a longitudinal projection extending rearward from a rear surface of the second panel, the longitudinal projection defining a bore formed along the longitudinal axis of the longitudinal projection at a distal end thereof, the longitudinal projection further defining a screw hole longitudinally extending through the bore of the longitudinal projection; a connection shaft including a proximal end portion configured to detachably insert within the bore of the longitudinal projection of the front board, an intermediate portion having a diameter configured to fit within the opening of the first panel of the rear board, and a distal end portion configured to fit within a central opening of the bearing, the connection shaft defining a hole longitudinally extending there-through; and a screw inserted through the longitudinal hole of the connection shaft and into the screw hole of the longitudinal projection of the front board for connecting the connection shaft and the front board.
The dart board assembly of the invention preferably includes a washer introduced between the head portion of the screw and the distal end portion of the connection shaft. The dart board assembly of the invention also preferably includes a peripheral projection extending rearward from the front board. In addition, the height of the longitudinal projection of the front board is preferably smaller than that of the peripheral projection 31 formed at the periphery of the front dart board.